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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    <a name="line.17"></a>
<FONT color="green">018</FONT>    package org.apache.commons.math3.stat.descriptive;<a name="line.18"></a>
<FONT color="green">019</FONT>    <a name="line.19"></a>
<FONT color="green">020</FONT>    import java.io.Serializable;<a name="line.20"></a>
<FONT color="green">021</FONT>    import java.util.Collection;<a name="line.21"></a>
<FONT color="green">022</FONT>    import java.util.Iterator;<a name="line.22"></a>
<FONT color="green">023</FONT>    <a name="line.23"></a>
<FONT color="green">024</FONT>    import org.apache.commons.math3.exception.NullArgumentException;<a name="line.24"></a>
<FONT color="green">025</FONT>    <a name="line.25"></a>
<FONT color="green">026</FONT>    /**<a name="line.26"></a>
<FONT color="green">027</FONT>     * &lt;p&gt;<a name="line.27"></a>
<FONT color="green">028</FONT>     * An aggregator for {@code SummaryStatistics} from several data sets or<a name="line.28"></a>
<FONT color="green">029</FONT>     * data set partitions.  In its simplest usage mode, the client creates an<a name="line.29"></a>
<FONT color="green">030</FONT>     * instance via the zero-argument constructor, then uses<a name="line.30"></a>
<FONT color="green">031</FONT>     * {@link #createContributingStatistics()} to obtain a {@code SummaryStatistics}<a name="line.31"></a>
<FONT color="green">032</FONT>     * for each individual data set / partition.  The per-set statistics objects<a name="line.32"></a>
<FONT color="green">033</FONT>     * are used as normal, and at any time the aggregate statistics for all the<a name="line.33"></a>
<FONT color="green">034</FONT>     * contributors can be obtained from this object.<a name="line.34"></a>
<FONT color="green">035</FONT>     * &lt;/p&gt;&lt;p&gt;<a name="line.35"></a>
<FONT color="green">036</FONT>     * Clients with specialized requirements can use alternative constructors to<a name="line.36"></a>
<FONT color="green">037</FONT>     * control the statistics implementations and initial values used by the<a name="line.37"></a>
<FONT color="green">038</FONT>     * contributing and the internal aggregate {@code SummaryStatistics} objects.<a name="line.38"></a>
<FONT color="green">039</FONT>     * &lt;/p&gt;&lt;p&gt;<a name="line.39"></a>
<FONT color="green">040</FONT>     * A static {@link #aggregate(Collection)} method is also included that computes<a name="line.40"></a>
<FONT color="green">041</FONT>     * aggregate statistics directly from a Collection of SummaryStatistics instances.<a name="line.41"></a>
<FONT color="green">042</FONT>     * &lt;/p&gt;&lt;p&gt;<a name="line.42"></a>
<FONT color="green">043</FONT>     * When {@link #createContributingStatistics()} is used to create SummaryStatistics<a name="line.43"></a>
<FONT color="green">044</FONT>     * instances to be aggregated concurrently, the created instances'<a name="line.44"></a>
<FONT color="green">045</FONT>     * {@link SummaryStatistics#addValue(double)} methods must synchronize on the aggregating<a name="line.45"></a>
<FONT color="green">046</FONT>     * instance maintained by this class.  In multithreaded environments, if the functionality<a name="line.46"></a>
<FONT color="green">047</FONT>     * provided by {@link #aggregate(Collection)} is adequate, that method should be used<a name="line.47"></a>
<FONT color="green">048</FONT>     * to avoid unnecessary computation and synchronization delays.&lt;/p&gt;<a name="line.48"></a>
<FONT color="green">049</FONT>     *<a name="line.49"></a>
<FONT color="green">050</FONT>     * @since 2.0<a name="line.50"></a>
<FONT color="green">051</FONT>     * @version $Id: AggregateSummaryStatistics.java 1416643 2012-12-03 19:37:14Z tn $<a name="line.51"></a>
<FONT color="green">052</FONT>     *<a name="line.52"></a>
<FONT color="green">053</FONT>     */<a name="line.53"></a>
<FONT color="green">054</FONT>    public class AggregateSummaryStatistics implements StatisticalSummary,<a name="line.54"></a>
<FONT color="green">055</FONT>            Serializable {<a name="line.55"></a>
<FONT color="green">056</FONT>    <a name="line.56"></a>
<FONT color="green">057</FONT>    <a name="line.57"></a>
<FONT color="green">058</FONT>        /** Serializable version identifier */<a name="line.58"></a>
<FONT color="green">059</FONT>        private static final long serialVersionUID = -8207112444016386906L;<a name="line.59"></a>
<FONT color="green">060</FONT>    <a name="line.60"></a>
<FONT color="green">061</FONT>        /**<a name="line.61"></a>
<FONT color="green">062</FONT>         * A SummaryStatistics serving as a prototype for creating SummaryStatistics<a name="line.62"></a>
<FONT color="green">063</FONT>         * contributing to this aggregate<a name="line.63"></a>
<FONT color="green">064</FONT>         */<a name="line.64"></a>
<FONT color="green">065</FONT>        private final SummaryStatistics statisticsPrototype;<a name="line.65"></a>
<FONT color="green">066</FONT>    <a name="line.66"></a>
<FONT color="green">067</FONT>        /**<a name="line.67"></a>
<FONT color="green">068</FONT>         * The SummaryStatistics in which aggregate statistics are accumulated.<a name="line.68"></a>
<FONT color="green">069</FONT>         */<a name="line.69"></a>
<FONT color="green">070</FONT>        private final SummaryStatistics statistics;<a name="line.70"></a>
<FONT color="green">071</FONT>    <a name="line.71"></a>
<FONT color="green">072</FONT>        /**<a name="line.72"></a>
<FONT color="green">073</FONT>         * Initializes a new AggregateSummaryStatistics with default statistics<a name="line.73"></a>
<FONT color="green">074</FONT>         * implementations.<a name="line.74"></a>
<FONT color="green">075</FONT>         *<a name="line.75"></a>
<FONT color="green">076</FONT>         */<a name="line.76"></a>
<FONT color="green">077</FONT>        public AggregateSummaryStatistics() {<a name="line.77"></a>
<FONT color="green">078</FONT>            // No try-catch or throws NAE because arg is guaranteed non-null<a name="line.78"></a>
<FONT color="green">079</FONT>            this(new SummaryStatistics());<a name="line.79"></a>
<FONT color="green">080</FONT>        }<a name="line.80"></a>
<FONT color="green">081</FONT>    <a name="line.81"></a>
<FONT color="green">082</FONT>        /**<a name="line.82"></a>
<FONT color="green">083</FONT>         * Initializes a new AggregateSummaryStatistics with the specified statistics<a name="line.83"></a>
<FONT color="green">084</FONT>         * object as a prototype for contributing statistics and for the internal<a name="line.84"></a>
<FONT color="green">085</FONT>         * aggregate statistics.  This provides for customized statistics implementations<a name="line.85"></a>
<FONT color="green">086</FONT>         * to be used by contributing and aggregate statistics.<a name="line.86"></a>
<FONT color="green">087</FONT>         *<a name="line.87"></a>
<FONT color="green">088</FONT>         * @param prototypeStatistics a {@code SummaryStatistics} serving as a<a name="line.88"></a>
<FONT color="green">089</FONT>         *      prototype both for the internal aggregate statistics and for<a name="line.89"></a>
<FONT color="green">090</FONT>         *      contributing statistics obtained via the<a name="line.90"></a>
<FONT color="green">091</FONT>         *      {@code createContributingStatistics()} method.  Being a prototype<a name="line.91"></a>
<FONT color="green">092</FONT>         *      means that other objects are initialized by copying this object's state.<a name="line.92"></a>
<FONT color="green">093</FONT>         *      If {@code null}, a new, default statistics object is used.  Any statistic<a name="line.93"></a>
<FONT color="green">094</FONT>         *      values in the prototype are propagated to contributing statistics<a name="line.94"></a>
<FONT color="green">095</FONT>         *      objects and (once) into these aggregate statistics.<a name="line.95"></a>
<FONT color="green">096</FONT>         * @throws NullArgumentException if prototypeStatistics is null<a name="line.96"></a>
<FONT color="green">097</FONT>         * @see #createContributingStatistics()<a name="line.97"></a>
<FONT color="green">098</FONT>         */<a name="line.98"></a>
<FONT color="green">099</FONT>        public AggregateSummaryStatistics(SummaryStatistics prototypeStatistics) throws NullArgumentException {<a name="line.99"></a>
<FONT color="green">100</FONT>            this(prototypeStatistics,<a name="line.100"></a>
<FONT color="green">101</FONT>                 prototypeStatistics == null ? null : new SummaryStatistics(prototypeStatistics));<a name="line.101"></a>
<FONT color="green">102</FONT>        }<a name="line.102"></a>
<FONT color="green">103</FONT>    <a name="line.103"></a>
<FONT color="green">104</FONT>        /**<a name="line.104"></a>
<FONT color="green">105</FONT>         * Initializes a new AggregateSummaryStatistics with the specified statistics<a name="line.105"></a>
<FONT color="green">106</FONT>         * object as a prototype for contributing statistics and for the internal<a name="line.106"></a>
<FONT color="green">107</FONT>         * aggregate statistics.  This provides for different statistics implementations<a name="line.107"></a>
<FONT color="green">108</FONT>         * to be used by contributing and aggregate statistics and for an initial<a name="line.108"></a>
<FONT color="green">109</FONT>         * state to be supplied for the aggregate statistics.<a name="line.109"></a>
<FONT color="green">110</FONT>         *<a name="line.110"></a>
<FONT color="green">111</FONT>         * @param prototypeStatistics a {@code SummaryStatistics} serving as a<a name="line.111"></a>
<FONT color="green">112</FONT>         *      prototype both for the internal aggregate statistics and for<a name="line.112"></a>
<FONT color="green">113</FONT>         *      contributing statistics obtained via the<a name="line.113"></a>
<FONT color="green">114</FONT>         *      {@code createContributingStatistics()} method.  Being a prototype<a name="line.114"></a>
<FONT color="green">115</FONT>         *      means that other objects are initialized by copying this object's state.<a name="line.115"></a>
<FONT color="green">116</FONT>         *      If {@code null}, a new, default statistics object is used.  Any statistic<a name="line.116"></a>
<FONT color="green">117</FONT>         *      values in the prototype are propagated to contributing statistics<a name="line.117"></a>
<FONT color="green">118</FONT>         *      objects, but not into these aggregate statistics.<a name="line.118"></a>
<FONT color="green">119</FONT>         * @param initialStatistics a {@code SummaryStatistics} to serve as the<a name="line.119"></a>
<FONT color="green">120</FONT>         *      internal aggregate statistics object.  If {@code null}, a new, default<a name="line.120"></a>
<FONT color="green">121</FONT>         *      statistics object is used.<a name="line.121"></a>
<FONT color="green">122</FONT>         * @see #createContributingStatistics()<a name="line.122"></a>
<FONT color="green">123</FONT>         */<a name="line.123"></a>
<FONT color="green">124</FONT>        public AggregateSummaryStatistics(SummaryStatistics prototypeStatistics,<a name="line.124"></a>
<FONT color="green">125</FONT>                                          SummaryStatistics initialStatistics) {<a name="line.125"></a>
<FONT color="green">126</FONT>            this.statisticsPrototype =<a name="line.126"></a>
<FONT color="green">127</FONT>                (prototypeStatistics == null) ? new SummaryStatistics() : prototypeStatistics;<a name="line.127"></a>
<FONT color="green">128</FONT>            this.statistics =<a name="line.128"></a>
<FONT color="green">129</FONT>                (initialStatistics == null) ? new SummaryStatistics() : initialStatistics;<a name="line.129"></a>
<FONT color="green">130</FONT>        }<a name="line.130"></a>
<FONT color="green">131</FONT>    <a name="line.131"></a>
<FONT color="green">132</FONT>        /**<a name="line.132"></a>
<FONT color="green">133</FONT>         * {@inheritDoc}.  This version returns the maximum over all the aggregated<a name="line.133"></a>
<FONT color="green">134</FONT>         * data.<a name="line.134"></a>
<FONT color="green">135</FONT>         *<a name="line.135"></a>
<FONT color="green">136</FONT>         * @see StatisticalSummary#getMax()<a name="line.136"></a>
<FONT color="green">137</FONT>         */<a name="line.137"></a>
<FONT color="green">138</FONT>        public double getMax() {<a name="line.138"></a>
<FONT color="green">139</FONT>            synchronized (statistics) {<a name="line.139"></a>
<FONT color="green">140</FONT>                return statistics.getMax();<a name="line.140"></a>
<FONT color="green">141</FONT>            }<a name="line.141"></a>
<FONT color="green">142</FONT>        }<a name="line.142"></a>
<FONT color="green">143</FONT>    <a name="line.143"></a>
<FONT color="green">144</FONT>        /**<a name="line.144"></a>
<FONT color="green">145</FONT>         * {@inheritDoc}.  This version returns the mean of all the aggregated data.<a name="line.145"></a>
<FONT color="green">146</FONT>         *<a name="line.146"></a>
<FONT color="green">147</FONT>         * @see StatisticalSummary#getMean()<a name="line.147"></a>
<FONT color="green">148</FONT>         */<a name="line.148"></a>
<FONT color="green">149</FONT>        public double getMean() {<a name="line.149"></a>
<FONT color="green">150</FONT>            synchronized (statistics) {<a name="line.150"></a>
<FONT color="green">151</FONT>                return statistics.getMean();<a name="line.151"></a>
<FONT color="green">152</FONT>            }<a name="line.152"></a>
<FONT color="green">153</FONT>        }<a name="line.153"></a>
<FONT color="green">154</FONT>    <a name="line.154"></a>
<FONT color="green">155</FONT>        /**<a name="line.155"></a>
<FONT color="green">156</FONT>         * {@inheritDoc}.  This version returns the minimum over all the aggregated<a name="line.156"></a>
<FONT color="green">157</FONT>         * data.<a name="line.157"></a>
<FONT color="green">158</FONT>         *<a name="line.158"></a>
<FONT color="green">159</FONT>         * @see StatisticalSummary#getMin()<a name="line.159"></a>
<FONT color="green">160</FONT>         */<a name="line.160"></a>
<FONT color="green">161</FONT>        public double getMin() {<a name="line.161"></a>
<FONT color="green">162</FONT>            synchronized (statistics) {<a name="line.162"></a>
<FONT color="green">163</FONT>                return statistics.getMin();<a name="line.163"></a>
<FONT color="green">164</FONT>            }<a name="line.164"></a>
<FONT color="green">165</FONT>        }<a name="line.165"></a>
<FONT color="green">166</FONT>    <a name="line.166"></a>
<FONT color="green">167</FONT>        /**<a name="line.167"></a>
<FONT color="green">168</FONT>         * {@inheritDoc}.  This version returns a count of all the aggregated data.<a name="line.168"></a>
<FONT color="green">169</FONT>         *<a name="line.169"></a>
<FONT color="green">170</FONT>         * @see StatisticalSummary#getN()<a name="line.170"></a>
<FONT color="green">171</FONT>         */<a name="line.171"></a>
<FONT color="green">172</FONT>        public long getN() {<a name="line.172"></a>
<FONT color="green">173</FONT>            synchronized (statistics) {<a name="line.173"></a>
<FONT color="green">174</FONT>                return statistics.getN();<a name="line.174"></a>
<FONT color="green">175</FONT>            }<a name="line.175"></a>
<FONT color="green">176</FONT>        }<a name="line.176"></a>
<FONT color="green">177</FONT>    <a name="line.177"></a>
<FONT color="green">178</FONT>        /**<a name="line.178"></a>
<FONT color="green">179</FONT>         * {@inheritDoc}.  This version returns the standard deviation of all the<a name="line.179"></a>
<FONT color="green">180</FONT>         * aggregated data.<a name="line.180"></a>
<FONT color="green">181</FONT>         *<a name="line.181"></a>
<FONT color="green">182</FONT>         * @see StatisticalSummary#getStandardDeviation()<a name="line.182"></a>
<FONT color="green">183</FONT>         */<a name="line.183"></a>
<FONT color="green">184</FONT>        public double getStandardDeviation() {<a name="line.184"></a>
<FONT color="green">185</FONT>            synchronized (statistics) {<a name="line.185"></a>
<FONT color="green">186</FONT>                return statistics.getStandardDeviation();<a name="line.186"></a>
<FONT color="green">187</FONT>            }<a name="line.187"></a>
<FONT color="green">188</FONT>        }<a name="line.188"></a>
<FONT color="green">189</FONT>    <a name="line.189"></a>
<FONT color="green">190</FONT>        /**<a name="line.190"></a>
<FONT color="green">191</FONT>         * {@inheritDoc}.  This version returns a sum of all the aggregated data.<a name="line.191"></a>
<FONT color="green">192</FONT>         *<a name="line.192"></a>
<FONT color="green">193</FONT>         * @see StatisticalSummary#getSum()<a name="line.193"></a>
<FONT color="green">194</FONT>         */<a name="line.194"></a>
<FONT color="green">195</FONT>        public double getSum() {<a name="line.195"></a>
<FONT color="green">196</FONT>            synchronized (statistics) {<a name="line.196"></a>
<FONT color="green">197</FONT>                return statistics.getSum();<a name="line.197"></a>
<FONT color="green">198</FONT>            }<a name="line.198"></a>
<FONT color="green">199</FONT>        }<a name="line.199"></a>
<FONT color="green">200</FONT>    <a name="line.200"></a>
<FONT color="green">201</FONT>        /**<a name="line.201"></a>
<FONT color="green">202</FONT>         * {@inheritDoc}.  This version returns the variance of all the aggregated<a name="line.202"></a>
<FONT color="green">203</FONT>         * data.<a name="line.203"></a>
<FONT color="green">204</FONT>         *<a name="line.204"></a>
<FONT color="green">205</FONT>         * @see StatisticalSummary#getVariance()<a name="line.205"></a>
<FONT color="green">206</FONT>         */<a name="line.206"></a>
<FONT color="green">207</FONT>        public double getVariance() {<a name="line.207"></a>
<FONT color="green">208</FONT>            synchronized (statistics) {<a name="line.208"></a>
<FONT color="green">209</FONT>                return statistics.getVariance();<a name="line.209"></a>
<FONT color="green">210</FONT>            }<a name="line.210"></a>
<FONT color="green">211</FONT>        }<a name="line.211"></a>
<FONT color="green">212</FONT>    <a name="line.212"></a>
<FONT color="green">213</FONT>        /**<a name="line.213"></a>
<FONT color="green">214</FONT>         * Returns the sum of the logs of all the aggregated data.<a name="line.214"></a>
<FONT color="green">215</FONT>         *<a name="line.215"></a>
<FONT color="green">216</FONT>         * @return the sum of logs<a name="line.216"></a>
<FONT color="green">217</FONT>         * @see SummaryStatistics#getSumOfLogs()<a name="line.217"></a>
<FONT color="green">218</FONT>         */<a name="line.218"></a>
<FONT color="green">219</FONT>        public double getSumOfLogs() {<a name="line.219"></a>
<FONT color="green">220</FONT>            synchronized (statistics) {<a name="line.220"></a>
<FONT color="green">221</FONT>                return statistics.getSumOfLogs();<a name="line.221"></a>
<FONT color="green">222</FONT>            }<a name="line.222"></a>
<FONT color="green">223</FONT>        }<a name="line.223"></a>
<FONT color="green">224</FONT>    <a name="line.224"></a>
<FONT color="green">225</FONT>        /**<a name="line.225"></a>
<FONT color="green">226</FONT>         * Returns the geometric mean of all the aggregated data.<a name="line.226"></a>
<FONT color="green">227</FONT>         *<a name="line.227"></a>
<FONT color="green">228</FONT>         * @return the geometric mean<a name="line.228"></a>
<FONT color="green">229</FONT>         * @see SummaryStatistics#getGeometricMean()<a name="line.229"></a>
<FONT color="green">230</FONT>         */<a name="line.230"></a>
<FONT color="green">231</FONT>        public double getGeometricMean() {<a name="line.231"></a>
<FONT color="green">232</FONT>            synchronized (statistics) {<a name="line.232"></a>
<FONT color="green">233</FONT>                return statistics.getGeometricMean();<a name="line.233"></a>
<FONT color="green">234</FONT>            }<a name="line.234"></a>
<FONT color="green">235</FONT>        }<a name="line.235"></a>
<FONT color="green">236</FONT>    <a name="line.236"></a>
<FONT color="green">237</FONT>        /**<a name="line.237"></a>
<FONT color="green">238</FONT>         * Returns the sum of the squares of all the aggregated data.<a name="line.238"></a>
<FONT color="green">239</FONT>         *<a name="line.239"></a>
<FONT color="green">240</FONT>         * @return The sum of squares<a name="line.240"></a>
<FONT color="green">241</FONT>         * @see SummaryStatistics#getSumsq()<a name="line.241"></a>
<FONT color="green">242</FONT>         */<a name="line.242"></a>
<FONT color="green">243</FONT>        public double getSumsq() {<a name="line.243"></a>
<FONT color="green">244</FONT>            synchronized (statistics) {<a name="line.244"></a>
<FONT color="green">245</FONT>                return statistics.getSumsq();<a name="line.245"></a>
<FONT color="green">246</FONT>            }<a name="line.246"></a>
<FONT color="green">247</FONT>        }<a name="line.247"></a>
<FONT color="green">248</FONT>    <a name="line.248"></a>
<FONT color="green">249</FONT>        /**<a name="line.249"></a>
<FONT color="green">250</FONT>         * Returns a statistic related to the Second Central Moment.  Specifically,<a name="line.250"></a>
<FONT color="green">251</FONT>         * what is returned is the sum of squared deviations from the sample mean<a name="line.251"></a>
<FONT color="green">252</FONT>         * among the all of the aggregated data.<a name="line.252"></a>
<FONT color="green">253</FONT>         *<a name="line.253"></a>
<FONT color="green">254</FONT>         * @return second central moment statistic<a name="line.254"></a>
<FONT color="green">255</FONT>         * @see SummaryStatistics#getSecondMoment()<a name="line.255"></a>
<FONT color="green">256</FONT>         */<a name="line.256"></a>
<FONT color="green">257</FONT>        public double getSecondMoment() {<a name="line.257"></a>
<FONT color="green">258</FONT>            synchronized (statistics) {<a name="line.258"></a>
<FONT color="green">259</FONT>                return statistics.getSecondMoment();<a name="line.259"></a>
<FONT color="green">260</FONT>            }<a name="line.260"></a>
<FONT color="green">261</FONT>        }<a name="line.261"></a>
<FONT color="green">262</FONT>    <a name="line.262"></a>
<FONT color="green">263</FONT>        /**<a name="line.263"></a>
<FONT color="green">264</FONT>         * Return a {@link StatisticalSummaryValues} instance reporting current<a name="line.264"></a>
<FONT color="green">265</FONT>         * aggregate statistics.<a name="line.265"></a>
<FONT color="green">266</FONT>         *<a name="line.266"></a>
<FONT color="green">267</FONT>         * @return Current values of aggregate statistics<a name="line.267"></a>
<FONT color="green">268</FONT>         */<a name="line.268"></a>
<FONT color="green">269</FONT>        public StatisticalSummary getSummary() {<a name="line.269"></a>
<FONT color="green">270</FONT>            synchronized (statistics) {<a name="line.270"></a>
<FONT color="green">271</FONT>                return new StatisticalSummaryValues(getMean(), getVariance(), getN(),<a name="line.271"></a>
<FONT color="green">272</FONT>                        getMax(), getMin(), getSum());<a name="line.272"></a>
<FONT color="green">273</FONT>            }<a name="line.273"></a>
<FONT color="green">274</FONT>        }<a name="line.274"></a>
<FONT color="green">275</FONT>    <a name="line.275"></a>
<FONT color="green">276</FONT>        /**<a name="line.276"></a>
<FONT color="green">277</FONT>         * Creates and returns a {@code SummaryStatistics} whose data will be<a name="line.277"></a>
<FONT color="green">278</FONT>         * aggregated with those of this {@code AggregateSummaryStatistics}.<a name="line.278"></a>
<FONT color="green">279</FONT>         *<a name="line.279"></a>
<FONT color="green">280</FONT>         * @return a {@code SummaryStatistics} whose data will be aggregated with<a name="line.280"></a>
<FONT color="green">281</FONT>         *      those of this {@code AggregateSummaryStatistics}.  The initial state<a name="line.281"></a>
<FONT color="green">282</FONT>         *      is a copy of the configured prototype statistics.<a name="line.282"></a>
<FONT color="green">283</FONT>         */<a name="line.283"></a>
<FONT color="green">284</FONT>        public SummaryStatistics createContributingStatistics() {<a name="line.284"></a>
<FONT color="green">285</FONT>            SummaryStatistics contributingStatistics<a name="line.285"></a>
<FONT color="green">286</FONT>                    = new AggregatingSummaryStatistics(statistics);<a name="line.286"></a>
<FONT color="green">287</FONT>    <a name="line.287"></a>
<FONT color="green">288</FONT>            // No try - catch or advertising NAE because neither argument will ever be null<a name="line.288"></a>
<FONT color="green">289</FONT>            SummaryStatistics.copy(statisticsPrototype, contributingStatistics);<a name="line.289"></a>
<FONT color="green">290</FONT>    <a name="line.290"></a>
<FONT color="green">291</FONT>            return contributingStatistics;<a name="line.291"></a>
<FONT color="green">292</FONT>        }<a name="line.292"></a>
<FONT color="green">293</FONT>    <a name="line.293"></a>
<FONT color="green">294</FONT>        /**<a name="line.294"></a>
<FONT color="green">295</FONT>         * Computes aggregate summary statistics. This method can be used to combine statistics<a name="line.295"></a>
<FONT color="green">296</FONT>         * computed over partitions or subsamples - i.e., the StatisticalSummaryValues returned<a name="line.296"></a>
<FONT color="green">297</FONT>         * should contain the same values that would have been obtained by computing a single<a name="line.297"></a>
<FONT color="green">298</FONT>         * StatisticalSummary over the combined dataset.<a name="line.298"></a>
<FONT color="green">299</FONT>         * &lt;p&gt;<a name="line.299"></a>
<FONT color="green">300</FONT>         * Returns null if the collection is empty or null.<a name="line.300"></a>
<FONT color="green">301</FONT>         * &lt;/p&gt;<a name="line.301"></a>
<FONT color="green">302</FONT>         *<a name="line.302"></a>
<FONT color="green">303</FONT>         * @param statistics collection of SummaryStatistics to aggregate<a name="line.303"></a>
<FONT color="green">304</FONT>         * @return summary statistics for the combined dataset<a name="line.304"></a>
<FONT color="green">305</FONT>         */<a name="line.305"></a>
<FONT color="green">306</FONT>        public static StatisticalSummaryValues aggregate(Collection&lt;SummaryStatistics&gt; statistics) {<a name="line.306"></a>
<FONT color="green">307</FONT>            if (statistics == null) {<a name="line.307"></a>
<FONT color="green">308</FONT>                return null;<a name="line.308"></a>
<FONT color="green">309</FONT>            }<a name="line.309"></a>
<FONT color="green">310</FONT>            Iterator&lt;SummaryStatistics&gt; iterator = statistics.iterator();<a name="line.310"></a>
<FONT color="green">311</FONT>            if (!iterator.hasNext()) {<a name="line.311"></a>
<FONT color="green">312</FONT>                return null;<a name="line.312"></a>
<FONT color="green">313</FONT>            }<a name="line.313"></a>
<FONT color="green">314</FONT>            SummaryStatistics current = iterator.next();<a name="line.314"></a>
<FONT color="green">315</FONT>            long n = current.getN();<a name="line.315"></a>
<FONT color="green">316</FONT>            double min = current.getMin();<a name="line.316"></a>
<FONT color="green">317</FONT>            double sum = current.getSum();<a name="line.317"></a>
<FONT color="green">318</FONT>            double max = current.getMax();<a name="line.318"></a>
<FONT color="green">319</FONT>            double m2 = current.getSecondMoment();<a name="line.319"></a>
<FONT color="green">320</FONT>            double mean = current.getMean();<a name="line.320"></a>
<FONT color="green">321</FONT>            while (iterator.hasNext()) {<a name="line.321"></a>
<FONT color="green">322</FONT>                current = iterator.next();<a name="line.322"></a>
<FONT color="green">323</FONT>                if (current.getMin() &lt; min || Double.isNaN(min)) {<a name="line.323"></a>
<FONT color="green">324</FONT>                    min = current.getMin();<a name="line.324"></a>
<FONT color="green">325</FONT>                }<a name="line.325"></a>
<FONT color="green">326</FONT>                if (current.getMax() &gt; max || Double.isNaN(max)) {<a name="line.326"></a>
<FONT color="green">327</FONT>                    max = current.getMax();<a name="line.327"></a>
<FONT color="green">328</FONT>                }<a name="line.328"></a>
<FONT color="green">329</FONT>                sum += current.getSum();<a name="line.329"></a>
<FONT color="green">330</FONT>                final double oldN = n;<a name="line.330"></a>
<FONT color="green">331</FONT>                final double curN = current.getN();<a name="line.331"></a>
<FONT color="green">332</FONT>                n += curN;<a name="line.332"></a>
<FONT color="green">333</FONT>                final double meanDiff = current.getMean() - mean;<a name="line.333"></a>
<FONT color="green">334</FONT>                mean = sum / n;<a name="line.334"></a>
<FONT color="green">335</FONT>                m2 = m2 + current.getSecondMoment() + meanDiff * meanDiff * oldN * curN / n;<a name="line.335"></a>
<FONT color="green">336</FONT>            }<a name="line.336"></a>
<FONT color="green">337</FONT>            final double variance;<a name="line.337"></a>
<FONT color="green">338</FONT>            if (n == 0) {<a name="line.338"></a>
<FONT color="green">339</FONT>                variance = Double.NaN;<a name="line.339"></a>
<FONT color="green">340</FONT>            } else if (n == 1) {<a name="line.340"></a>
<FONT color="green">341</FONT>                variance = 0d;<a name="line.341"></a>
<FONT color="green">342</FONT>            } else {<a name="line.342"></a>
<FONT color="green">343</FONT>                variance = m2 / (n - 1);<a name="line.343"></a>
<FONT color="green">344</FONT>            }<a name="line.344"></a>
<FONT color="green">345</FONT>            return new StatisticalSummaryValues(mean, variance, n, max, min, sum);<a name="line.345"></a>
<FONT color="green">346</FONT>        }<a name="line.346"></a>
<FONT color="green">347</FONT>    <a name="line.347"></a>
<FONT color="green">348</FONT>        /**<a name="line.348"></a>
<FONT color="green">349</FONT>         * A SummaryStatistics that also forwards all values added to it to a second<a name="line.349"></a>
<FONT color="green">350</FONT>         * {@code SummaryStatistics} for aggregation.<a name="line.350"></a>
<FONT color="green">351</FONT>         *<a name="line.351"></a>
<FONT color="green">352</FONT>         * @since 2.0<a name="line.352"></a>
<FONT color="green">353</FONT>         */<a name="line.353"></a>
<FONT color="green">354</FONT>        private static class AggregatingSummaryStatistics extends SummaryStatistics {<a name="line.354"></a>
<FONT color="green">355</FONT>    <a name="line.355"></a>
<FONT color="green">356</FONT>            /**<a name="line.356"></a>
<FONT color="green">357</FONT>             * The serialization version of this class<a name="line.357"></a>
<FONT color="green">358</FONT>             */<a name="line.358"></a>
<FONT color="green">359</FONT>            private static final long serialVersionUID = 1L;<a name="line.359"></a>
<FONT color="green">360</FONT>    <a name="line.360"></a>
<FONT color="green">361</FONT>            /**<a name="line.361"></a>
<FONT color="green">362</FONT>             * An additional SummaryStatistics into which values added to these<a name="line.362"></a>
<FONT color="green">363</FONT>             * statistics (and possibly others) are aggregated<a name="line.363"></a>
<FONT color="green">364</FONT>             */<a name="line.364"></a>
<FONT color="green">365</FONT>            private final SummaryStatistics aggregateStatistics;<a name="line.365"></a>
<FONT color="green">366</FONT>    <a name="line.366"></a>
<FONT color="green">367</FONT>            /**<a name="line.367"></a>
<FONT color="green">368</FONT>             * Initializes a new AggregatingSummaryStatistics with the specified<a name="line.368"></a>
<FONT color="green">369</FONT>             * aggregate statistics object<a name="line.369"></a>
<FONT color="green">370</FONT>             *<a name="line.370"></a>
<FONT color="green">371</FONT>             * @param aggregateStatistics a {@code SummaryStatistics} into which<a name="line.371"></a>
<FONT color="green">372</FONT>             *      values added to this statistics object should be aggregated<a name="line.372"></a>
<FONT color="green">373</FONT>             */<a name="line.373"></a>
<FONT color="green">374</FONT>            public AggregatingSummaryStatistics(SummaryStatistics aggregateStatistics) {<a name="line.374"></a>
<FONT color="green">375</FONT>                this.aggregateStatistics = aggregateStatistics;<a name="line.375"></a>
<FONT color="green">376</FONT>            }<a name="line.376"></a>
<FONT color="green">377</FONT>    <a name="line.377"></a>
<FONT color="green">378</FONT>            /**<a name="line.378"></a>
<FONT color="green">379</FONT>             * {@inheritDoc}.  This version adds the provided value to the configured<a name="line.379"></a>
<FONT color="green">380</FONT>             * aggregate after adding it to these statistics.<a name="line.380"></a>
<FONT color="green">381</FONT>             *<a name="line.381"></a>
<FONT color="green">382</FONT>             * @see SummaryStatistics#addValue(double)<a name="line.382"></a>
<FONT color="green">383</FONT>             */<a name="line.383"></a>
<FONT color="green">384</FONT>            @Override<a name="line.384"></a>
<FONT color="green">385</FONT>            public void addValue(double value) {<a name="line.385"></a>
<FONT color="green">386</FONT>                super.addValue(value);<a name="line.386"></a>
<FONT color="green">387</FONT>                synchronized (aggregateStatistics) {<a name="line.387"></a>
<FONT color="green">388</FONT>                    aggregateStatistics.addValue(value);<a name="line.388"></a>
<FONT color="green">389</FONT>                }<a name="line.389"></a>
<FONT color="green">390</FONT>            }<a name="line.390"></a>
<FONT color="green">391</FONT>    <a name="line.391"></a>
<FONT color="green">392</FONT>            /**<a name="line.392"></a>
<FONT color="green">393</FONT>             * Returns true iff &lt;code&gt;object&lt;/code&gt; is a<a name="line.393"></a>
<FONT color="green">394</FONT>             * &lt;code&gt;SummaryStatistics&lt;/code&gt; instance and all statistics have the<a name="line.394"></a>
<FONT color="green">395</FONT>             * same values as this.<a name="line.395"></a>
<FONT color="green">396</FONT>             * @param object the object to test equality against.<a name="line.396"></a>
<FONT color="green">397</FONT>             * @return true if object equals this<a name="line.397"></a>
<FONT color="green">398</FONT>             */<a name="line.398"></a>
<FONT color="green">399</FONT>            @Override<a name="line.399"></a>
<FONT color="green">400</FONT>            public boolean equals(Object object) {<a name="line.400"></a>
<FONT color="green">401</FONT>                if (object == this) {<a name="line.401"></a>
<FONT color="green">402</FONT>                    return true;<a name="line.402"></a>
<FONT color="green">403</FONT>                }<a name="line.403"></a>
<FONT color="green">404</FONT>                if (object instanceof AggregatingSummaryStatistics == false) {<a name="line.404"></a>
<FONT color="green">405</FONT>                    return false;<a name="line.405"></a>
<FONT color="green">406</FONT>                }<a name="line.406"></a>
<FONT color="green">407</FONT>                AggregatingSummaryStatistics stat = (AggregatingSummaryStatistics)object;<a name="line.407"></a>
<FONT color="green">408</FONT>                return super.equals(stat) &amp;&amp;<a name="line.408"></a>
<FONT color="green">409</FONT>                       aggregateStatistics.equals(stat.aggregateStatistics);<a name="line.409"></a>
<FONT color="green">410</FONT>            }<a name="line.410"></a>
<FONT color="green">411</FONT>    <a name="line.411"></a>
<FONT color="green">412</FONT>            /**<a name="line.412"></a>
<FONT color="green">413</FONT>             * Returns hash code based on values of statistics<a name="line.413"></a>
<FONT color="green">414</FONT>             * @return hash code<a name="line.414"></a>
<FONT color="green">415</FONT>             */<a name="line.415"></a>
<FONT color="green">416</FONT>            @Override<a name="line.416"></a>
<FONT color="green">417</FONT>            public int hashCode() {<a name="line.417"></a>
<FONT color="green">418</FONT>                return 123 + super.hashCode() + aggregateStatistics.hashCode();<a name="line.418"></a>
<FONT color="green">419</FONT>            }<a name="line.419"></a>
<FONT color="green">420</FONT>        }<a name="line.420"></a>
<FONT color="green">421</FONT>    }<a name="line.421"></a>




























































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